Comments on: Number of IPv6 addresseshttp://itknowledgeexchange.techtarget.com/itanswers/number-of-ipv6-addresses/
Sun, 02 Aug 2015 08:47:57 +0000hourly1By: tomliottahttp://itknowledgeexchange.techtarget.com/itanswers/number-of-ipv6-addresses/#comment-79503
Thu, 22 Jul 2010 02:38:51 +0000#comment-79503IPv4 addresses are mapped as 32-bit numbers. IPv6 addresses are mapped as 128-bit numbers. In both cases, there are ranges of addresses as well as individual specific addresses that are reserved.

Regardless, you can think of the number of IPv6 addresses as being the number of IPv4 addresses raised to the 4th power.

Think of IPv4 addresses being reserved (used up) over the past ten years. In fact, let’s say it only took five years to use them all. We might then estimate that in the next five years, we’ll need twice as many addresses.

So, we come up with a new scheme that uses 33-bit numbers instead of 32-bit numbers, and we now have twice as many to work with. But five years isn’t long enough to plan, so let’s double the number again to use 34-bit numbers. Now we have four times as many and we can last four times as long — 20 years to exhaust them instead of just five years.

35-bit numbers doubles it again to 40 years. 36-bits gets to 80 years. Each bit doubles everything before (at the current rate of exhaustion).

But the jump was from 32 bits to 128 bits.

A single doubling was enough to assign an IP address to every currently living human being. Another doubling gave two addresses apiece, and another gave four. 8, 16, 32, 64, 128… by the time it gets anywhere close to 128 bits, we’re getting in the range of estimates of the number of atoms in the known universe which is far more than enough to have a separate address for every atom on earth.

Anyone may make whatever guesses they choose about when IPv6 addresses will run out.

Tom

]]>By: mattmatherhttp://itknowledgeexchange.techtarget.com/itanswers/number-of-ipv6-addresses/#comment-79288
Fri, 16 Jul 2010 16:47:15 +0000#comment-79288359 days till X day when we will run out of IPv4 addresses (10th July 2011).

When it comes to IPv6 addresses, we have assigned roughly 140’000 /32 (by January 2010) and that makes up for 0.02% of the IPv6 address space. Note that 140’000 /32 means, that is more than 140’000 times the whole IPv4 address space. Information: http://www.bgpexpert.com/addrspace-ipv6-2009.php